The invention relates to a spray nozzle and, more particularly, to a nozzle for directing a pressurized spray of atomized liquid into the atmosphere in the form of extremely small particles.
Systems for atomizing liquid with a pressurized gas such as air are known. In certain ones of such systems, the liquid is broken up both mechanically and by the pressurized air in an atomizing chamber located upstream of the spray nozzle. The atomized liquid then is ejected from the nozzle through one or more discharge openings in the nozzle.
An often-sought goal in atomizing and spraying apparatus is to achieve high efficiency. High efficiency in the context of the present invention refers to using as little air energy as possible to break liquid of a given volume into particles having a large total surface area. Larger surface areas are, of course, created by breaking the liquid into very fine particles.
A further goal is to provide nozzles having the capability of discharging the liquid in different spray patterns. By way of example, some applications require a narrow angle round spray, other applications may require a wide angle round spray (i.e., a full cone spray) and still other applications may require a flat spray.
In prior atomizing/spraying apparatus, the desired spray pattern is usually generated by forcing the atomized liquid through properly shaped discharge orifice means in the nozzle. A narrow angle round spray, for example, may be created by providing the nozzle with a single round orifice. A wide angle round spray may be generated by a nozzle having a plurality of angularly spaced diverging orifices. An elongated slot or an elliptically shaped orifice in the discharge nozzle produces a substantially flat spray pattern.
Nozzles having discharge orifices of the above type are essentially passive with respect to effecting further atomization of the liquid as the liquid is discharged from the nozzle. Certain nozzles do produce some further atomization during flow of the liquid through the nozzle but, for the most part, the atomization effected by the nozzle has limited impact on the overall efficiency of the atomizing and spraying apparatus.